/Engine/Source/Runtime/Engine/Classes/Kismet/KismetMathLibrary.h
Linearly interpolates between A and B based on Alpha (100% of A when Alpha=0 and 100% of B when Alpha=1)
static [FLinearColor](API\Runtime\Core\Math\FLinearColor) LinearColorLerp ( [FLinearColor](API\Runtime\Core\Math\FLinearColor) A, [FLinearColor](API\Runtime\Core\Math\FLinearColor) B, float Alpha )